Untreated water may contain pathogenic microorganisms such as bacteria, viruses, parasites, or parasite eggs, and it may also contain some chemical components harmful to the human body. After drinking this unsanitary untreated water, one is prone to illness. After being heated and boiled, pathogenic microorganisms are killed, and some harmful chemical components are decomposed by heat, greatly reducing or eliminating the possibility of causing disease in the human body.
Spoiled beverages contain a large amount of bacterial growth. The toxic and harmful products produced by these bacteria can cause human poisoning, leading to symptoms such as dizziness, headache, nausea, vomiting, abdominal pain, diarrhea, high fever, and convulsions, and can even be life-threatening. Therefore, spoiled beverages should not be consumed.